Directions
Butter a 13-in. x 9-in. pan with 1 tablespoon butter; set aside. In a large heavy saucepan, combine the sugar, milk and remaining butter. Bring to a full boil over medium heat; boil for 2 minutes, stirring constantly.

Remove from the heat. Stir in marshmallows until melted. Add chocolate chips and unsweetened chocolate; stir until chips are melted. Add nuts and vanilla.

Spread into prepared pan. Cool for 1 hour at room temperature. Cut into squares. Store in an airtight container in the refrigerator. Yield: 5 pounds.